Discussion:
Diagnosis of SARS‐CoV‐2 is done by RTPCR testing . However, there is
limited availability and high cost of RTPCR testing for SARS‐CoV‐2, in
addition to its potentially high false negative rate of patients
clinically diagnosed with COVID‐19. Furthermore, the RT‐PCR results
showed a fluctuating trend (4). The timely transfer patients to ICU or a
designated unit (isolation or quarantine) that has sufficient rescue
equipments should be considered even if their results of RT‐PCR test for
pharyngeal swab specimens are negative to limit the spread of infection.
Therefore, the need for rapid bed-side diagnostic tools is highly
appreciated. In this study we put for the first time a high sensitive
score for suspicion of SARS‐CoV‐2 infection using bed-side investigation
tools as chest X ray and lung ULS. A single clinician would be necessary
to perform an initial medical assessment and imaging investigation
directly at the patient’s bed.
Lung ULS can help in reducing the number of health care professionals
exposed during patient stratification by simple rapid bed side test
(14)(15).
Lung ULS could be done without patient immobilization that might spread
the infection. This differs from CT chest that requires patient
mobilization and may be difficult in critical ventilated patients, in
addition to its radiation hazards and high cost.
To the best of our knowledge, there is only one case report describing
the findings of lung ULS in confirmed Covid 19 patient and reporting an
irregular pleural line with small subpleural consolidations, areas of
white lung and thick, confluents and irregular vertical artifacts
(B-lines)(15).
Although our findings carry variable findings, however our results found
that A profile and abnormal A lines in lung ULS are independent
predictors for Covid 19 infection.
Our score has high sensitivity (93.8%) in detection of Covid 19
infection making it a good negative test.
Lung ULS was reported to have 86% diagnostic accuracy in detecting
alveolar consolidation and was able to differentiate between effusion
and consolidation. Its specificity for detecting consolidation reached
100% in some studies (11).
Regarding the prognosis of Covid 19 infected patients, we analyzed the
predictors for mortality as long as prolonged hospitalization. Old age,
presence of cardiac problem and hypoxia on admission are clinical
predictors of mortality. This is concordant with previous reports
(7)(16).
Concerning lung ULS, we present for the first time imaging predictors
for mortality using this simple, safe and cheap tool in Covid 19
patients.
In our study B lung ULS profile and abnormal A lines were associated
with mortality.
Abnormal A lines was also correlated with prolonged hospitalization.
This also may direct the medical staff to determine patients needing
high care and those that may need long hospital stay.
Regarding other investigation, CT chest shows more consolidation and
ground glass appearance in Covid 19 infected patients. This is
consistent with other reports in which the prominent radiologic
abnormalities were bilateral
ground-glass opacity and subsegmental consolidation areas (8)(17).
Our laboratory findings showed that Covid 19 infected patients had less
blood O2 saturation and less lymphocytic count than other causes of
pneumonia. However, in our study lymphopenia has not reach the
significant degree of correlation with mortality. Other reports showed
predominance of lymphopenia in Covid 19 infection among critical than
other less critical patients and is associated with severe course
(7)(18). In a study conducted with Zhou et al, they found that baseline
lymphocyte count was significantly higher in survivors than
non-survivors of Covid 19 infected patients. However in survivors,
lymphocyte count improved after the 1st week of illness, whereas severe
lymphopenia remained until death in non-survivors(7).